In Obelix and Co, a devious young Roman general, Caius Preposterus (a thinly veiled Jacques Chirac) tries to corrupt Asterix's proud Gaulish village by making the inhabitants compete for money and status. It is tempting to regard Albert Uderzo's announcement that he will, despite previously insisting otherwise, allow others to continue writing and illustrating the Asterix adventures, as the equivalent of our ageing hero abandoning the village, and handing over Getafix's magic potion to the Romans.

But it's rather more remarkable that Uderzo kept Asterix going so long on his own. Part historical fantasy, part a kind of Private Eye, packed with the harmless violence of "pafs" and "tchocs", the world of Asterix was a unique dual creation. Multilingual René Goscinny brought the literary allusions – there's an entire page of Caesar's Gift where Asterix duels a Roman soldier in the style of Cyrano de Bergerac. Uderzo matched him with meticulously researched and drawn landscapes, architecture and visual puns, such as the reference to Géricault's painting The Raft of the Medusa in Asterix the Legionary.

Because it looked as good, we ignored the fact that most of the stories, apart from a couple of notable exceptions (Asterix and the Black Gold, Asterix and the Great Divide) were much poorer after Goscinny died in 1977.

Like Marvel Comics' Stan Lee, Uderzo at 84 seems driven by a legitimate desire to consolidate the financial possibilities against a ticking clock, but with what some fans would regard as a disappointing disregard for the spirit of the original.

Just as Lee's Marvel studios stopped selling their heroes to the big Hollywood studios, in favour of their own, sometimes just as dumb films and fast food tie-ins, Uderzo licensed the wild boar-eating symbol of French anti-imperial resistance to market Le Big Mac. It just seems wrong.

But then, like Marvel Studios wisely bringing in Kenneth Branagh to inject some Shakespearean grandeur into Thor, Uderzo has overseen a new lease of life for Asterix in live action films. No less than France's most famous thespian Gerard Depardieu has returned to portray big, dumb loveable Obelix who fell in the magic potion as a baby.

Like Lee, too, Uderzo deserves recognition for the scale of his achievement; much of it in the long-running Pilote comic, where Asterix first appeared. A master draftsman and a cinematic storyteller, in his use of epic set pieces, cutaways and closeups, he's drawn 400 unique characters to date in Asterix alone.

He revels in all the variants of Gallic physiognomy (bullying Crismus Bonus in Asterix the Gaul looks unnervingly like Dominique Strauss-Kahn) but Uderzo, born of Italian immigrant parents, also delighted in national types; the separate tribes who join together to fight the global corporatisation and arrogance of the Roman empire. From the moustachioed, hot water-drinking Britons to the proud Corsicans with their dangerous cheeses Uderzo has gently mocked, but also shown affection for, individuals who stay true to themselves. So after so many years, would it have been better to have said it just ends with me, as Charles M Schulz did with Peanuts?

Renowned English translator Anthea Bell's collaboration with Goscinny and Uderzo dates back to the 1960s. She said last year that Uderzo had already cleared the principle with publishers Hachette that the Asterix brand would continue with new writers and artists. She's said she has qualms about it, but that it's none of her business.

Take a closer look at other much-loved animated brands and we see how often something looks the same, but has been debased when the creator's gone. Roger Hargreaves's Mr Men (their 40th anniversary was marked on the Today programme no less) grew massively after his death. Easy to draw, the brightly coloured smiling shapes on a carousel of "collect them all" books prove that you can make a fortune in children's cartoons without content.

The Rev Wilbert Awdry's Thomas the Tank Engine stories fascinated tiny children. In the 1990s his heirs launched cheap and nasty cartoon toddler books, as part of a massive media and merchandising expansion. But Thomas has in little over 10 years gone through boom and bust. Now it's just one of many once-cherished British brands, including the Mr Men and Bagpuss, currently up for grabs in faceless international corporate firesales. Is that what lies in wait for Asterix?

We want Asterix to resist forever but that can only happen if the books stop. It's time to break the sentimental link. The inhabitants of the Gaullish village can no longer hold out. Perhaps Preposterous was right. In the end it's all about money.